V6 max output volume

Im trying to get some insight into highspeed printing and im testing how much I can actually extrude.
Given we use a original v6 with .4 nozzle at .2 hight and .48 width, what would be the max speed we can drive filament though.

Through my own experiments that limit would be somewhere between 10 and 15ccm/s but I never found other experiments that confirm that. Anyone ever seen a test like that?

that makes sense.
would you say that the volcano is bound to the same max volume?
I when I tested it recently and looked a the volume formula the max speed was directly proportional lower compared to my normal .4 setup. i kind of expected over proportional output due to the different heating architecture.

wow i did not expect that number. the last time i printed with the 1.2 nozzle I didnt come over 18mm³/s. what happened I describe in this thread https://forum.e3d-online.com/index.php?threads/1-2mm-nozzle-extrusion-fail.1635/
and I narrowed it down to the heater block not being able to supply heat consistently. also my bowden tube would never stay in place at those volumes. I already have a 2 clips on the hotend side and im working on a 2nd one on the hotends side as well but that seems to good to be true